Field of the Disclosure
The present disclosure relates to an electrophotographic electro-conductive member, a process cartridge, and an electrophotographic apparatus.
Description of the Related Art
In an electrophotographic apparatus, which is an image-forming apparatus employing an electrographic system, an electro-conductive member is applied to a variety of uses, for example, use as an electro-conductive roller, such as a charging roller, developing roller, or a transferring roller. These electro-conductive rollers are required to have an electric resistance value of 103 to 1010Ω and are provided with elastic layers containing electro-conductive particles, such as carbon black, for adjusting the conductivity of the electro-conductive layers. The electric resistance value of electro-conductive particles readily varies depending on the dispersed state, and stabilization of the electric resistance value of an electro-conductive member may be difficult in some cases.
If an electro-conductive member is abutted against, for example, a photosensitive member in an electrophotographic apparatus, continuous and intermittent repeating compression is applied to the elastic layer. As a result, in some cases, the dispersed state of the electro-conductive particles, such as carbon black, changes to cause a change in the electric resistance value. Japanese Patent Laid-Open No. 2008-256908 discloses an electro-conductive member composed of polar rubber and carbon black dispersed therein at optimized DBP absorption amount, particle diameter, and amount for preventing the variation in the electric resistance value of the electro-conductive member.
One embodiment of the present disclosure is directed to providing an electro-conductive member for electrophotography which can prevent change in an electric resistance value even in long time use. Another embodiment of the present disclosure is directed to providing a process cartridge and an electrophotographic apparatus both of which can provide a high quality electrophotographic image for a long time.